implement and use new macros BN_get_sign(), BN_set_sign()

Submitted by: Nils Larsch

crypto/dsa/dsa_ossl.c

diff --git a/crypto/dsa/dsa_ossl.c b/crypto/dsa/dsa_ossl.c
index 37dd5fc..fc35dfe 100644
--- a/crypto/dsa/dsa_ossl.c
+++ b/crypto/dsa/dsa_ossl.c
@@ -246,12 +246,14 @@
 	BN_init(&u2);
 	BN_init(&t1);
 
-	if (BN_is_zero(sig->r) || sig->r->neg || BN_ucmp(sig->r, dsa->q) >= 0)
+	if (BN_is_zero(sig->r) || BN_get_sign(sig->r) ||
+	    BN_ucmp(sig->r, dsa->q) >= 0)
 		{
 		ret = 0;
 		goto err;
 		}
-	if (BN_is_zero(sig->s) || sig->s->neg || BN_ucmp(sig->s, dsa->q) >= 0)
+	if (BN_is_zero(sig->s) || BN_get_sign(sig->s) ||
+	    BN_ucmp(sig->s, dsa->q) >= 0)
 		{
 		ret = 0;
 		goto err;